///
// Version 3: Dynamic programming version
///
int edit_distance3(char *s1, char *s2) {
int i, j;
int opt[3];
for (i = 0; i < MAX; ++i) {
row_init(i);
column_init(i);
}
for (i = 1; i < strlen(s1); ++i) {
for (j = 1; j < strlen(s2); ++j) {
opt[MATCH] = m[i - 1][j - 1].cost + match(s1[i], s2[j]);
opt[INSERT] = m[i][j - 1].cost + del(s2[j]);
opt[DELETE] = m[i - 1][j].cost + ins(s1[i]);
m[i][j].cost = opt[MATCH];
m[i][j].parent = MATCH;
for(int k = INSERT; k <= DELETE; ++k) {
if (opt[k] < m[i][j].cost) {
m[i][j].cost = opt[k];
m[i][j].parent = k;
}
}
}
}
goal_cell(s1, s2, &i, &j);
return m[i][j].cost;
}
int string_compare(char *s, char *t)
{
uint i, j, k;
int opt[3];
for (i = 0; i < MAXLEN; i++) {
row_init(i);
column_init(i);
}
//print_matrix(s, t, TRUE);
for (i = 1; i < strlen(s); i++) {
for (j = 1; j < strlen(t); j++) {
opt[MATCH] = m[i-1][j-1].cost + match(s[i], t[j]);
opt[INSERT] = m[i][j-1].cost + indel(t[j]);
opt[DELETE] = m[i-1][j].cost + indel(s[i]);
m[i][j].cost = opt[MATCH];
m[i][j].parent = MATCH;
for (k = INSERT; k <= DELETE; k++) {
if (opt[k] < m[i][j].cost) {
m[i][j].cost = opt[k];
m[i][j].parent = k;
}
}
}
}
goal_cell(s, t, &i, &j);
return m[i][j].cost;
}
int string_compare(char *s, char *t)
{
int i,j,k; /* counters */
int opt[3]; /* cost of the three options */
for (i=0; i<MAXLEN; i++) {
row_init(i);
column_init(i);
}
for (i=1; i<strlen(s); i++)
for (j=1; j<strlen(t); j++) {
opt[MATCH] = m[i-1][j-1].cost + match(s[i],t[j]);
opt[INSERT] = m[i][j-1].cost + indel(t[j]);
opt[DELETE] = m[i-1][j].cost + indel(s[i]);
m[i][j].cost = opt[MATCH];
m[i][j].parent = MATCH;
for (k=INSERT; k<=DELETE; k++)
if (opt[k] < m[i][j].cost) {
m[i][j].cost = opt[k];
m[i][j].parent = k;
}
}
goal_cell(s,t,&i,&j);
return( m[i][j].cost );
}
int main(void) {
int i, j;
char s[MAXLEN], t[MAXLEN]; /* input strings */
s[0] = t[0] = ' ';
scanf("%s", &(s[1])); scanf("%s", &(t[1]));
printf("matching cost = %d \n", string_compare(s, t));
print_matrix(s, t, TRUE); printf("\n"); print_matrix(s, t, FALSE);
goal_cell(s, t, &i, &j); printf("%d %d\n", i, j);
reconstruct_path(s,t, i ,j); printf("\n");
return 0;
}
// return the edit distance for changing s into t by means of matching, swapping,
// changing, inserting, or deleting chars.
int string_compare(char* s, char* t)
{
int i,j,k;
int opt[5];
for (i = 0; i < MAXLEN; i++)
{
row_init(i);
column_init(i);
}
for (i = 1; i < strlen(s); i++)
{
for (j = 1; j < strlen(t); j++)
{
opt[MATCH] = m[i-1][j-1].cost + match(s[i],t[j]);
opt[SWAP] = m[i-1][j-1].cost + swap(s, t, i);
opt[CHANGE] = m[i-1][j-1].cost + 1;
opt[INSERT] = m[i][j-1].cost + 1;
opt[DELETE] = m[i-1][j].cost + 1;
m[i][j].cost = opt[MATCH];
m[i][j].parent = MATCH;
for (k = SWAP; k <= DELETE; k++)
{
if (opt[k] < m[i][j].cost)
{
// if the last in-place action was a swap, and this action is a
// change, then we are actually continuing the swap. Swap changes
// two characters for a cost of one, so we change the first char for
// 1, and change the second char for 0.
if (k == CHANGE && m[i-1][j-1].parent == SWAP)
m[i][j].cost = m[i-1][j-1].cost;
// otherwise it's the least cost action, as identified
else
m[i][j].cost = opt[k];
m[i][j].parent = k;
}
}
}
}
goal_cell(s,t,&i,&j);
return(m[i][j].cost);
}
main() {
int i,j;
char s[MAXLEN],t[MAXLEN]; /* input strings */
s[0] = t[0] = ' ';
printf("enter p :\n");
scanf("%s",&(s[1]));
printf("enter t :\n");
scanf("%s",&(t[1]));
printf("matching cost = %d \n", string_compare(s,t, strlen(s)-1,strlen(t)-1));
print_matrix(s,t,TRUE);
printf("\n");
print_matrix(s,t,FALSE);
goal_cell(s,t,&i,&j);
printf("%d %d\n",i,j);
reconstruct_path(s,t,i,j);
printf("\n");
}
